1. Field of the Invention:
The present invention relates generally to handling nuclear fuel pellets and, more particularly, is concerned with an apparatus for loading newly made (green) friable nuclear fuel pellets into sintering boats from a pellet press.
2. Description of the Prior Art:
An operational step in the nuclear fuel fabrication process is the loading of friable nuclear fuel pellets, which have been ejected from the die table surface of a pellet press, into sintering boats (containers) in preparation for high temperature firing of the pellets in a sintering furnace. This operation requires careful handling of the pellets, because the pre-sintered pellets are easily crumbled.
Typical nuclear fuel pellet loading devices are disclosed in U.S. Pat. Nos. 4,332,120 and 4,566,835, both hereby incorporated by reference. The loader described in U.S. Pat. No. 4,332,120 employs a vertical chute which has a set of zig-zag inclined plates to guide the pellets into a boat which rests on a spring-biased platform. The loader described in U.S. Pat. No. 4,566,835 employs a horizontally disposed drum which receives a line of pellets into a vertically aligned lengthwise channel and which discharges the line of pellets into a boat when the drum rotates the channel to a below horizontal position.
It is known in the prior art to load nuclear fuel pellets into a sintering boat by a gravity discharge from the pellet press down an inclined chute (having perpendicular sides) into the boat. Pellet impeding devices (such as feeler stock and paint brushes) hanging vertically down onto the pellet path along the chute have been generally unsuccessful in reducing pellet impact.
What is needed is an economical, soft-pellet-handling sintering boat pellet loader, one which releases the pellets with near-zero velocity above the sintering boat, and one which operates passively without motorized arrangements and simply without a multiplicity of parts.